A specific absorption rate (Specific Absorption Rate, referred to as SAR) refers to a ratio at which electromagnetic wave energy of a wireless communications terminal is absorbed. It is usually used as an indicator to measure intensity of electromagnetic radiation when the wireless communications terminal approaches a body: A greater SAR value indicates a greater impact on the human body; contrarily, the impact is smaller. The SAR has become one of the contents marked on a product package or a product manual by terminal vendors in many countries and regions.
As more and more wireless communications devices such as a mobile phone, a data card, a tablet PC and so on, enter people's life, people gradually become aware that electromagnetic radiation generated by such communications devices has many negative effects on health of the body when they enjoy a variety of conveniences brought by the wireless communications devices. For example, too much electromagnetic radiation causes functional disorder of a central nervous system of a person, and brings symptoms such as a headache, insomnia and so on. At present, an excess of standard of the SAR value of a wireless terminal has become a big problem in the industry. The SAR value of the wireless terminal is relevant to a test distance (a distance between a radiator and a human body model) and transmit power, that is, in a case that the transmit power is the same, the smaller the test distance is, the greater the SAR value is. Therefore, to solve the foregoing problem, the wireless terminal vendors usually adopt the following solutions: reducing the transmit power of the wireless terminal; and increasing a thickness of the overall terminal (indirectly increasing the test distance).
However, apparently, wireless radiation power (Total Radiation Power, referred to as TRP) is decreased when the transmit power of the wireless terminal is reduced, thereby reducing wireless performance of the wireless terminal. Increasing the thickness of the overall terminal may affect use experience of a user, while a tendency of the wireless terminal is to be compact, ultra-thin, and portable; therefore, apparently, increasing the thickness of the overall terminal cannot be accepted by the user.